1. Field of the Invention
The present invention relates to a system of valves for regulating and controlling the amount of a pressurized fluid within a system of air bags used as a suspension system for a trailer. Specifically, the system consists of a series of valves for fluidly connecting and disconnecting suspension air bags from a pressurized air source.
2. Prior Art
In the trucking industry, trailers are typically fitted with air bags above their axles. These air bags support the cargo portion of the trailer. They are typically supplied with pressurized air from the same source that supplies air to the air brakes. If one of the air bags breaks or forms a leak, the air supply is depleted. This results in all four air bags losing air. It also results in loss of air pressure to the air brakes, causing them to lock up and forcing the truck to stop. When this occurs on the open road, a repair vehicle must be sent out to the truck to repair the damaged air bag. This is both very expensive and very time consuming.
The prior art discloses a number of various air bags and similar devices and methods for controlling fluid inflow and outflow therefrom.
U.S. Pat. No. 2,691,420 issued to Fox on Jul. 2, 1949 discloses an arrangement especially designed to render more practicable the application to and installation in a large bus or motor coach of constant level pneumatic springs. Provision is made for increasing or decreasing the pressure of each supporting air column.
U.S. Pat. No. 3,246,905 issued to Morgan on Apr. 19, 1966 discloses an apparatus and method for supporting variable static loads by a fluid pressure spring-shock absorber including thermoelectrically controlled vapor pressure varying means and lock-out control means.
U.S. Pat. No. 3,302,980 issued by Bystricky Feb. 7, 1967 discloses a valve means for use in apparatus having a plurality of pressurized fluid operated devices, and is more particularly directed to a quick-opening, quick-closing valve which is operable automatically under the influence of fluid pressure to open and to close a port in response to predetermined pressure variations, which automatic operation may be manually overridden to positively close the port, when desired.
U.S. Pat. No. 3,433,493 issued to Hist on Jan. 4, 1967 discloses a road vehicle suspension system having interconnected front and rear fluid springs which maintain a given vehicle body attitude regardless of differing dynamic deflections of the front and rear suspensions.
U.S. Pat. No. 4,054,327 issued to Rebenstorf on Oct. 18, 1977 discloses an air brake system for a vehicle with a plurality of air-operated brakes for retaining braking capacity in the event of line rupture or severe leakage at various points in the system. Brake control means, preferably of the form with two separately actuatable control valves each independently capable of actuating the brakes, has two check valve-protected air-receiving ports each coupled to a separate one of two reservoirs.
U.S. Pat. No. 4,070,644 issued to Shellhause on Jan. 24, 1978 discloses a dual circuit brake system having a failure warning section in which the pressures in each of the circuits are sensed by a pair of pistons having a switch actuating shuttle positioned between the pistons by a pair of springs. If the cause of pressure loss was a leak or rupture in a portion of the rear brake system beyond outlet 28, the closing of valve 50 will effectively prevent undue brake fluid loss through that portion of the system.
U.S. Pat. No. 4,252,379 issued to Falk on Feb. 24, 1981 discloses a pressure control valve for use in vehicle hydraulic diagonal split brake systems. The control valve further includes second valve means which will be disposed in the second fluid branch of the dual brake system to transit fluid pressure at the second inlet to the second outlet and to limit the fluid pressure transmitted to the second outlet relative to the fluid pressure at the second inlet when the fluid pressure at the second inlet is above the predetermined level.
U.S. Pat. No. 5,005,858 issued to Torrielli on Apr. 9, 1991 discloses a hydro pneumatic suspension system able to vary at will, and independently of each other, the rigidity of the sustaining and load-adaptation means of each vehicle wheel, consisting of a series of sensors for measuring the dynamic attitude of the vehicle connected to a central electronic control unit, and respective hydraulic dampers of adjustable internal pressure, which support the wheels and are connected to respective hydro pneumatic service accumulators the internal pressure of which is controlled by solenoid valves controlled by the central control unit; hydraulic energy can be supplied to the accumulators by, for example, the servo-steering system pump via a common main accumulator. As the valves 32 are independently controlled, non-symmetrical load variations on the wheels of the same axle can be compensated, irrespective of how these occur, and it is possible to vary the load transfer between the two axles so as to influence the behavior of the vehicle when taking a bend (under-steering, over-steering).
U.S. Pat. No. 5,640,990 issued to Rodriguez on Jun. 24, 1997 discloses a safety valve for precluding leakage of a fluid from a ruptured conduit and provides a flexible conduit failure safety valve which has many of the advantages of automatic valve structures that result in a flexible conduit failure safety valve.
U.S. Pat. No. 5,855,379 issued on Buma on Jan. 5, 1999 discloses a control system of an automotive vehicle including a vehicle height control apparatus for adjusting height of the vehicle under control of fluid under pressure supplied from a first fluid pump and a brake control apparatus for regulating braking forces applied to a set of road wheels of the vehicle under control of fluid under pressure supplied from a second fluid pump, wherein a single source of driving force in the form of an electric motor is adapted in common to the first and second control apparatuses to drive both the first and second fluid pumps.
U.S. Pat. No. 6,354,617 issued to Behmenburg on Mar. 12, 2002 discloses a level control arrangement having a pneumatically controllable directional valve which contains an over pressure function and a residual pressure holding function and which makes a rapid deflation or venting of the air springs possible.
U.S. Pat. No. 6,523,845 issued to Stiller on Feb. 25, 2003 discloses a method of filling a pressurized medium chamber of a level control system which includes a pressurized medium store and a compressor. The pressurized medium chamber is filled from the pressurized medium store over a time span during which the pressurized medium difference between the pressurized medium store and the pressurized medium chamber exceeds a threshold valve. When the pressurized medium difference between the pressurized medium store and the pressurized medium chamber reaches the threshold value, a further filling of the pressurized medium chamber is necessary and takes place by means of the compressor of the level control system.
None of the prior art patents disclose a system for use on tractor trailers that allows an operator to manually isolate any chosen individual air bag while inflating others. None of the prior art patents disclose an air bag regulating system for tractor trailers that allow the pressurized air source to power pneumatically driven tools and air to the tires. The prior art also does not disclose a system for allowing the air bags to be adjusted so that a trailer may continue moving in the event of a failure of a wheel bearing, tire blow out, broken axle, or similar malfunction.
It is therefore desirable to provide a system for regulating the air pressure with air bags on a trailer.
It is also desirable to provide a device that allows a trailer to continue traveling in the event of a failure of a wheel bearing, tire blowout, broken axle, or similar malfunction.
It is also desirable to provide a method for allowing a tractor pressure ride air source to power pneumatic tools and to inflate tires.